Leslie St. Spit is a bird nerd’s paradise. The man-made peninsula curling out from the foot of the Port Lands has become internationally famous for its ornithological riches, home — or at least hotel — to both migratory beauties like the Cedar Waxwing and threatened Ontario birds like the Least Bittern, a kind of heron.

But that claim to fame is under threat, not by foresters or skyscraper windowpanes, but by an invasive plant with a menacing name. For the last few years, Phragmites australis has been gnawing away at the native vegetation of Tommy Thompson Park, located on the Spit. That’s hurting a handful of important bird species who rely on the local mud flats and bulrushes for food and shelter.

For now, Tommy Thompson park authorities have all but given up on fighting phrag, as it’s known. According to Karen McDonald, a project manager with the Toronto and Region Conservation Authority (TRCA), which operates Tommy Thompson Park, “We aren’t taking any action to control it, simply because it’s so difficult to control.”

The phrag invasion is not limited to the Spit — it’s been spreading throughout Ontario for decades. Feasting on moisture, the plant proliferates in wetlands and marshes, along lakeshores, and in the disturbed soil bordering highways. Stands have been reported as far north as Sudbury in the east and Fort Frances in the west.

Though the European plant is not new to the province, its rapid spread has raised alarm this summer. Stoptheinvasion.ca, a website dedicated to phrag eradication, went live on July 31. “Giant aliens have invaded Lake Huron, and they’re coming to destroy your and my shoreline,” intones a man in the site’s introductory video.

Phragmites is vicious towards other plants, a predator that crowds out other vegetation and creates monocultures. A towering, homely beast that can reach up to six metres in height, phrag thrives under a much wider range of conditions than most other wetland plants. Just for good measure, its roots also release toxins into the soil to stunt and kill nearby flora.

“Phragmites is a super competitor,” said McDonald. “It out-competes native vegetation for nutrients.”

On the Spit, the native vegetation is rich and varied: bulrushes, burr reeds, cattails, elderberry, dogwood. It’s a beautiful sight, but it’s also habitat for the 316 migratory or resident bird species that have passed through or live on the peninsula.

McDonald said phrag has been present in the park for over a decade, but became a real problem about five years ago. “It was around 2009 that we started to see a true invasion into Cell 1,” she said, referring to the lush artificial wetland completed in 2005.

The phragmites incursion is bad news for shorebirds because it swallows the muddy border between water and shore that’s flush with nutritious insects.

And ducks take a hit because they like to nest in Ontario’s familiar bulrushes, which are often muscled out by phrag stands.

“It may be limiting the use by marsh birds currently as the wetland matures,” McDonald said.

The migratory species whose profusion in the spring draws birdwatchers from far and wide could also see their food sources snapped up by the dreaded phragmites.

Paula Davies, president of East York’s Todmorden Mills Wildflower Preserve — also phrag-afflicted — fears for the Spit’s migrating warblers (and over the years the site has seen Tennessee, Mourning, Orange-crowned, Magnolia, and at least a dozen others).

“They need food when they come over the Great Lakes,” she said. “Elderberry and dogwoods have so many insects on them, it’s like McDonald’s.”

The TRCA has tried all manner of things to clear the park of phrag.

For a while, conservation staff tried injecting the stems of individual plants with herbicide, but that was too labour-intensive.

“We also experimented with trying to mechanically remove it,” said McDonald — that is, digging it out with a shovel — but that didn’t work either.

Mowing down stands only made them grow back more robustly, and flooding the plants would also kill much of the native vegetation that McDonald and her team are trying to preserve.

So for now, phrag can proliferate on the Spit unabated — the TRCA has stopped trying to beat it back. And while McDonald said the reeds were likely not spreading over any new ground, they are probably growing denser, tightening their stranglehold on the life-giving plants that have made the area a bird haven.

“It continues to worsen,” McDonald said.

Facts about Phragmites

The species to worry about is Phragmites australis, originally from Europe — a native strain, Americanus, has been in North America since before Columbus, and is “not considered a problem,” according to the Ontario Ministry of Natural Resources and Forestry.

The earliest records of Phragmites australis in Canada come from Annapolis Royal, N.S., in 1910. Some Maritimers called it “elephant grass” because it was thought to be spread by trains carrying circus animals.

Good news! The Spit’s birds may be in trouble, but the peninsula’s equally lovely butterfly population is likely to escape the phrag invasion mostly unscathed. Because milkweed, their food of choice, prefers dry conditions, it has little competition from the aggressive reed.

With files from Leslie Scrivener

More on thestar.com

We value respectful and thoughtful discussion. Readers are encouraged to flag comments that fail to meet the standards outlined in our
Community Code of Conduct.
For further information, including our legal guidelines, please see our full website
Terms and Conditions.